//
// * Copyright (c) 2002-2009 "Neo Technology,"
// *     Network Engine for Objects in Lund AB [http://neotechnology.com]
// *
// * This file is part of Neo4j.
// * 
// * Neo4j is free software: you can redistribute it and/or modify
// * it under the terms of the GNU Affero General Public License as
// * published by the Free Software Foundation, either version 3 of the
// * License, or (at your option) any later version.
// * 
// * This program is distributed in the hope that it will be useful,
// * but WITHOUT ANY WARRANTY; without even the implied warranty of
// * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// * GNU Affero General Public License for more details.
// * 
// * You should have received a copy of the GNU Affero General Public License
// * along with this program. If not, see <http://www.gnu.org/licenses/>.
// 
namespace org.neo4j.kernel.impl.transaction.xaframework
{


///
/// <summary> * During recovery (after system crash) the <seealso cref="XaLogicalLog"/> will examine
/// * the the logical log and re-create any transaction that didn't complete.
/// * <CODE>XaCommandFactory</CODE> job is to read in commands from the logical
/// * log and re-create them. </summary>
/// 
	public abstract class XaCommandFactory
	{
///    
///     <summary> * Reads the data from a commad previosly written to the logical log and
///     * creates the command again.
///     * <p>
///     * The implementation has to guard against the command beeing corrupt and
///     * not completly written to the logical log. When unable to read the command
///     * <CODE>null</CODE> should be returned. <CODE>IOException</CODE> should
///     * only be thrown in case of real IO failure. The <CODE>null</CODE> return
///     * is a signal to the recovery mechanism to stop scaning for more entries.
///     *  </summary>
///     * <param name="fileChannel">
///     *            The channel to read the command data from </param>
///     * <param name="buffer">
///     *            A small buffer that can be used to read data into </param>
///     * <returns> The command or null if unable to read command </returns>
///     * <exception cref="IOException">
///     *             In case of real IO failure </exception>
///     
//JAVA TO VB & C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public abstract XaCommand readCommand(ReadableByteChannel byteChannel, ByteBuffer buffer) throws IOException;
		public abstract XaCommand readCommand(ReadableByteChannel byteChannel, ByteBuffer buffer);
	}
}